Gas mileage on carburated 350ci K5 Blazers?

Curious as to what sort of in town and highway gas mileage you guys are seeing on your carburated 350ci K5 rigs. This one of mine has a tired old 305ci in it and I figure I'll be pulling that engine and replacing it with a 350 next Spring.

My logic is that a 350 will pull the weight of the truck a lot easier than the 305 will. But maybe my thinking is flawed?

Well with a too big untuned carb and a fresh tight motor I got 147 miles to a 30 gallon fill up. After putting on a smaller carb and tuning it, fixing my timeing airing up my tires fixing some other minor problems I got 370 out of a 30 gallon fill up. Now my choke is stuck and so is my high idle /forums/images/graemlins/angryfire.gif and I got about 80 miles out of my fill up /forums/images/graemlins/angryfire.gif

I have a K10 Longbed with a 350 sbc, th350, np203 and 4.09 gears with 35" BFG's w/ 6" lift and I get 11mpg Highway /forums/images/graemlins/cool.gif, 9mpg town /forums/images/graemlins/frown.gif and 6-7mpg Offroad /forums/images/graemlins/pimp1.gif. It is a stock long block with an edelbrock performer manifold and 600cfm carb jetted for 5000 ft.

With my 83 which has 305, 700r4, and stock 3.08 gears (I'm poor). I get around 15 mpg combined. Oh and I am running 32 inch tires. It's best to keep it tuned right and filters changed. Logic would dictate that as long as both engines are in good order , the bigger one would have an easier job with the extra torque the engine has ( horsepower = torque x rpm / 5252 ). Torque is more important than horsepower in a general all around truck.

i have a 83 k20 with a 350 with only 600 miles on it with th350/np208 3.42 gears and 265 75 16 and i get 12.5 highway /forums/images/graemlins/eek.gif i will be putting a 700r4 it tommorow and maybe ill get better gallons per mile

I am running a TBI 350 block and heads about 90K on the engine with an Edelbrock performer intake and Edelbrock 600CFM performer carb that is well tuned with a 700R4/203 combo/ 4.56's and 36's and I average about 10-12mpg on the highway. That is when I am gentle with the long skinny, if I driving it hard I can get it all the way down to about 5mpg /forums/images/graemlins/eek.gif /forums/images/graemlins/rotfl.gif

6 to 9 in town, 10 to 13 on the highway, all depending on throttle. I have a pumped 406, 700R4, 4.10's and 35" boggers. Edel. q-jet. Hopefully it will jump up a few with multi port FI. I used to have a 350 and mileage was considerably better than with my 406.

No /forums/images/graemlins/frown.gif, at least not this fuel injected guy. 88' K5, freshly rebuilt 355TBI with vortec heads, TES headers, 700R4 that's not in the greatest shape, NP208, stock 3.42s, 31X11.50 AT's, and getting around 11 city. 2 years ago when I bought this tank it was getting around 13 city (before I started taking things apart). But in the K5's defense the EGR system isn't hooked up, the AIR system has long been removed, and she most likely needs a custom chip to run at her prime.

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